With the development of organic light-emitting diode (OLED) display technologies, the resolution of display panels is required to be higher and higher. The resolution of an OLED display panel is usually expressed as the product of the number of pixels in a horizontal direction and the number of pixels in a vertical direction. A pixel traditionally consists of three sub-pixels, i.e., a red (R) sub-pixel, a green (G) sub-pixel, and a blue (B) sub-pixel. In order to realize high-resolution performance, density of sub-pixels in a display panel adopting a traditional RGB pixel arrangement must be multiplied. This can greatly increase difficulty and cost in manufacturing the display panel.